The 2003 Presidential Commission Report on the Future of the USPS concluded that the Postal Service should continue to develop effective mailstream merging systems that optimize efficiency, e.g., maximize the number of mailpieces shipped with each mile traveled, while minimizing the labor content associated with mailpiece handling. With respect to the latter, all elements of the mail stream (letters, flats, periodicals, post cards, etc,) should be sorted, merged, and/or sequenced with the expectation that no subsequent handling would be required at each of the local postal branch offices, i.e., other than the physical delivery to the recipient address.
Most postal services are actively exploring opportunities to reduce the overall cost of processing mail by investing in postal automation equipment, particularly in postal automation associated with mailpiece sorting processes. While significant progress has been made sorting conventional letter-size mailpieces, the remaining mailpieces, e.g., magazines, periodicals, newspapers, catalogues and other flats-size mailpieces, often are not machinable and must be hand sorted. While only twenty-percent (20%) of the mailstream may be catagorized as “non-machinable”, the time required to handle and sort such mailpieces is equal to or greater than the time spent sorting the other eighty percent (80%) of the mailstream.
Certain mailpieces are deemed non-machinable for two principal reasons. First, singulating mailpieces such as magazines and newspapers can present difficulties inasmuch as a portion of these mailpieces are unbound or unconstrained, that is, they have free-edges. As such, even small shear forces applied for the purpose of separating the mailpieces, can cause individual sheets or pages to be wrinkled, torn or otherwise damaged. Secondly, when such mailpieces are handled in the feeder, individual sheets or pages are prone to jam during sorting operations.
To combat the difficulties associated with handling these mailpieces, the mail entering automated postal equipment must be “prepared”, before sorting operations can begin. Preparation may include a process of culling mailpieces which are likely to stall or jam the sorting equipment, or, alternatively, packaging mailpieces so as to facilitate separation and/or reduce the propensity for jamming. For example, magazines or newspapers may be wrapped or enclosed within a larger envelope to capture or contain the free-edges of the mailpiece. While these activities can prepare mailpieces for automated processing, the labor expense can completely offset or nullify the fiscal benefits derived by such automated handling equipment.
The following documents disclose various systems and subsystems of a mail sorter capable of handling all varieties of mail, i.e., a mixed-mail sorter: WO 2006/063204, WO 2006/063121, WO 2006/063125, WO 2006/110486, WO 2006/110465, and WO 2006/110484. One of the most essential features of the mixed mail sorter relates to the use of a clamping assembly operative to secure, transport, divert, sort and release the mailpieces. in addition to its principle mechanical functions, the clamps also include a means to uniquely identify the clamp and its associated mailpiece. As such, the sorting operation may be performed by a combination of requisite information, i.e., electronically scanned information in connection with the mailpiece (e.g., its destination address) together with the unique identifier of the clamp. Further, the sorting process may be performed without altering/marking the mailpiece, such as via a printed barcode symbology or other identification mark.
Having described the functional significance of the clamping assembly, it will also be appreciated that a mailpiece should be centered within a clamp assembly to obviate certain handling difficulties/inconsistencies. More specifically, it will be understood that the gravitational center of the combined clamp/mailpiece assembly will rotate about the overhead conveyor bar (i.e., acting as a support pivot) such that all moments/forces are in equilibrium. When the centroid of the mailpiece is misaligned relative to the centerline of the clamp assembly, the combined clamp/mailpiece assembly may assume a skewed orientation (i.e., relative to the vertical) when the assembly is hung from the overhead conveyor bar. As such, difficulties may arise when attempting to divert the mailpiece to a subsequent conveyor bar or release the mailpiece into a bin/container.
While, in prior art mail sorters, it is generally known to align mailpieces along one or two edges, e.g., in register along adjacent edges or along a corner thereof, no methods or systems are currently available to accurately center a mailpiece within a clamp assembly. That is, there has been no physical requirement, heretofore, to align the geometric center or centroid of a mailpiece with the gravitational center of the clamp assembly.
A need, therefore, exists for an apparatus and method for positioning or centering an object/mailpiece to a desired reference position so as to ensure predictable conveyance and release of objects/mailpieces while being manipulated by automated handling equipment.